Histamine Agonists

	Histamine Agonists A histamine agonist is a drug which causes increased activity at one or more of the four histamine receptor subtypes. H1 agonists promote wakefulness. H2: Betazole and Impromidine are examples of agonists used in diagnostics to increase histamine. H3: Betahistine is a weak Histamine1 agonist and a very strong antagonist of the Histamine3 autoreceptor. Antagonizing H3 increases histaminergic tone. See also * Histamine antagonist Antihistamines are drugs which treat allergic rhinitis, common cold, influenza, and other allergies. Typically, people take antihistamines as an inexpensive, generic (not patented) drug that can be bought without a prescription and provides r ... References External links * * {{pharmacology-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu]
	Histamine Receptor The histamine receptors are a class of G protein–coupled receptors which bind histamine as their primary endogenous ligand. Histamine is a neurotransmitter involved in various physiological processes. There are four main types of histamine receptors: H1, H2, H3, and H4. H1 receptors are linked to allergic responses, H2 to gastric acid regulation, H3 to neurotransmitter release modulation, and H4 to immune system function. There are four known histamine receptors: histamine H1 receptor, H1 receptorPrimarily located on Smooth muscle, smooth muscle cells, endothelial cells, and neurons. Activation of H1 receptors mediates various responses, including smooth muscle contraction (leading to bronchoconstriction, intestinal cramping), increased vascular permeability (resulting in edema), and stimulation of sensory nerve endings (causing itching and pain). H1 antagonists, commonly known as antihistamines, are used to alleviate symptoms of allergies and allergic reactions.S histamine H2 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu]
	Betazole Betazole (also known as ametazole) is a histamine H2 receptor agonist. Betazole hydrochloride is known as gastramine and histalog. It has been used as a gastric stimulant to test for maximal production of gastric secretion activity. The test can be used in diagnosis of diseases such as Zollinger-Ellison syndrome where there is excess acid production, in this case driven by over production of gastrin. The volume of acid secretion is measured following administration of betazole, diagnosis being secretion greater than 60% of the maximal acid secretion following betazole stimulation. This procedure can lead to complications and should be avoided in subjects with coronary artery disease. It is also used in diagnosis of gastritis in association with a test for secretin activity. Betazole is used as a stimulant in preference to histamine because of its specificity for the H2 receptor and its advantage of not generating the undesirable side effects that histamine would induce. It t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu]
	Impromidine Impromidine (INN) is a highly potent and specific histamine H2 receptor agonist. It has been used diagnostically as a gastric secretion indicator. See also * Histamine agonists A histamine agonist is a drug which causes increased activity at one or more of the four histamine receptor subtypes. H1 agonists promote wakefulness. H2: Betazole and Impromidine are examples of agonists used in diagnostics to increase histam ... References Imidazoles Guanidines Thioethers {{gastrointestinal-drug-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu]
	Betahistine Betahistine, sold under the brand name Serc among others, is an anti-vertigo medication. It is commonly prescribed for balance disorders or to alleviate vertigo symptoms. It was first registered in Europe in 1970 for the treatment of Ménière's disease, but current evidence does not support its efficacy in treating it. Medical uses Betahistine was once believed to have some positive effects in the treatment of Ménière's disease and vertigo, but more recent evidence casts doubt on its efficacy. Studies of the use of betahistine have shown a reduction in symptoms of vertigo and, to a lesser extent, tinnitus, but conclusive evidence is lacking at present. Oral betahistine has been approved for the treatment of Ménière's disease and vestibular vertigo in more than 80 countries worldwide, and has been reportedly prescribed for more than 130 million patients. However, betahistine has not been approved for marketing in the United States for the past few decades, and there is disa ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu]
	Autoreceptor An autoreceptor is a type of Receptor (biochemistry), receptor located in the cell membrane, membranes of neuron, nerve cells. It serves as part of a negative feedback loop in signal transduction. It is only sensitive to the neurotransmitters or hormones released by the neuron on which the autoreceptor sits. Similarly, a heteroreceptor is sensitive to neurotransmitters and hormones that are not released by the cell on which it sits. A given receptor can act as either an autoreceptor or a heteroreceptor, depending upon the type of transmitter released by the cell on which it is embedded. Autoreceptors may be located in any part of the cell membrane: in the dendrites, the perikaryon, cell body, the axon, or the axon terminals. Canonically, a presynaptic neuron releases a neurotransmitter across a synaptic cleft to be detected by the receptors on a postsynaptic neuron. Autoreceptors on the presynaptic neuron will also detect this neurotransmitter and often function to control intern ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu]
	Histamine Antagonist Antihistamines are drugs which treat allergic rhinitis, common cold, influenza, and other allergies. Typically, people take antihistamines as an inexpensive, generic (not patented) drug that can be bought without a prescription and provides relief from nasal congestion, sneezing, or hives caused by pollen, dust mites, or animal allergy with few side effects. Antihistamines are usually for short-term treatment. Chronic allergies increase the risk of health problems which antihistamines might not treat, including asthma, sinusitis, and lower respiratory tract infection. Consultation of a medical professional is recommended for those who intend to take antihistamines for longer-term use. Although the general public typically uses the word "antihistamine" to describe drugs for treating allergies, physicians and scientists use the term to describe a class of drug that opposes the activity of histamine receptors in the body. In this sense of the word, antihistamines are subclassif ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu]